Besides the fact that it only has one USB port, I don't think 2.1A is going to be enough to charge both a phone and a tablet at the same time. I think the S3 uses a 1A charger, and most tablets use 2-2.1A, so if you were to somehow connect both to this device they would charge much slower than normal, if at all. You'd want something with around 3A(and two ports) to reliably charge a phone and tablet simultaneously.

However, another review said modifications are needed to get your device to charge in AC mode rather than USB mode(which is limited to something like 500mA). I actually hadn't known about the difference between AC and USB charging modes, so I did some testing with the two external batteries and cheap car charger I have.

For my phone, both of the external batteries I have (a VAAS 5000mAh 2.1/1A unit, and a cheap 1.5A unit that claims 4400mAh from eBay) would only charge in USB mode, while the generic 1A car charger I have charged in AC mode. I then tried the same test with my tablet and was a little surprised by the results - everything was able to charge it in AC mode. The only exception was connecting it to my desktop PC, which engaged USB charging, although that may be because it connects as a media device for data transfer. I actually tried to cancel my order after I read some of the reviews, but it was already marked "shipping soon" so it looks like I'm stuck. I'll try the same test when they arrive if I don't end up refusing the shipment.

As the resident charging expert i will Explain a few things about chargers and high current charging mode:

Industry standards are: to enable high current charging you need to have the 2 data lines shorted together. This tells the tablet/phone its not plugged into a usb port(500ma limit).

However no one goes by standards. So there trick is they put a voltage divider on the shorted data pins from the 5v/ground connections so that there is 2-4v on the data lines. This way you have to use their charger.

So what i do is mod the "standard" chargers with 2 resistors of equal value and pop them inbetween the data lines and 5v/ground. so they sit at 2.5v, which is good enough for all devices.

As for the 2amp thing. A dead tablet will suck 2amp till its 20% charged(15min tops), then it sucks 1.5amps, by 50% charge its down to 1amp, by 75% you are lucky to be sucking 200ma. This is a linear graph, i just noted some points.

In other news my favorite charger is the tmobile premium 3amp model with 2 usb slots. Its got the blank pads for the 2.5v mod on the datalines already so its real easy to mod.

For anyone wondering about the New Trent dual 1/2.1A 15W charger I linked above[amazon.com], I got mine in today and did some informal testing. I used my phone (Samsung Galaxy Nexus), tablet (Nexus 7), and OEM/generic micro USB cables. My phone would only charge in USB mode, regardless of the port or cable used, while my tablet charged in AC mode with the OEM cables(both Samsung and ASUS) on both ports, but would only charge in USB mode with the generic cable included with the charger. The tablet results were somewhat expected, but it was strange that my phone wouldn't charge in AC mode with this charger when it did so with the generic one I've been using. I wanted to monitor the actual current, but none of the battery monitoring apps I tried worked with either my phone or tablet for displaying mA/A.

Am I missing something? Can't you get a USB car charger for $2 any day now and use whatever cables you want?

In iLanguage, this can charge iPads at 2.1 amps, and iPhones at 1 amp, instead of the standard, low (normal) power of 0.5 amp.

Apparently this charger's abilities is recognized by the iDevice, so the iDevice can determine that it can draw 1 or 2 amps. If the charger isn't recognized, the iDevice may draw 0.5 amps, or maybe none.

My phone would only charge in USB mode, regardless of the port or cable used, while my tablet charged in AC mode with the OEM cables(both Samsung and ASUS) on both ports, but would only charge in USB mode with the generic cable included with the charger.

Maybe the generic cable only contained the power connections, and not the data ones, so the tablet wasn't able to determine that the charger could deliver more power. Maybe the phone used a different mechanism (than say, Apple uses) for determining the charger's abilities. Maybe I'm just pulling random answers out of my orifice.

Found a Deal?
Slickdeals is able to share the best deals because of the contributions of users like you! If you found a great deal,
please share it with others by posting in our forums.

First Time?
Welcome to Slickdeals!
Save money here by finding the lowest and cheapest price, best deals and bargains, and hot coupons. We're all about
community driven bargain hunting with thousands of free discounts, promo codes, reviews and price comparisons.

Don't worry, we'll help you find your way. If you haven't already, check out this
user guide
that explains the features of our site.